Organopolysiloxanes which have been prepared by condensation and/or equilibration of organosilicon compounds containing Si-bonded oxygen in the presence of phosphazenes as catalysts generally change their molecular weight during storage, and thus change their viscosity, if the phosphazenes are not deactivated or removed after the reaction. For example, U.S. Pat. No. 3,398,176 (issued on Aug. 20, 1968, Wacker-Chemie GmbH) discloses the deactivation of phosphazenes, described as phosphonitrilic chlorides, by reaction with tertiary mines. DE-A 34 28 581 (laid open on Feb. 13, 1986, Wacker-Chemie GmbH) describes the stabilization with basic lithium compounds, such as lithium hydroxide or lithium siloxanolates, of organopolysiloxanes prepared using phosphazenes. DE-A 37 42 069 (laid open on Jun. 22, 1989, Wacker-Chemie GmbH) is an example of the numerous patents describing deactivation of phosphazene catalysts using silazanes, e.g., hexamethyldisilazane or 1,3-divinyl- 1,1,3,3-tetramethyldisilazane. A further method of stabilizing organopolysiloxanes which have been prepared using phosphazene catalysts is reaction with oxides, hydroxides or carbonates of divalent and trivalent metals, e.g., magnesium oxide, which is described in DE-A 35 33 028 (laid open on Mar. 19, 1987, Wacker-Chemie GmbH). EP-B 0 117 503 (published on May 13, 1987, Wacker-Chemie GmbH) discloses deactivation of phosphazene catalysts using epoxides.
In the processes mentioned for stabilizing organopolysiloxanes prepared using phosphazenes or phosphonitrilic chlorides, use is made of compounds which react with the acid catalysts. With the exception of the neutral epoxides, these are all basic substances. In most processes, the reaction products of phosphazene catalyst and deactivation agent remain completely or partially in the organopolysiloxanes, only in the process described in DE-A 35 33 028 are they removed.